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A gramphone record is revolving with an ...

A gramphone record is revolving with an angular velocity omega. A coin is placed at a distance `r` from the centre of the record. The static coefficient of friction is mu. The coin will revolve with the record if.

A

`r=mugomega^(2)`

B

`rltomega^(2)/(mug)`

C

`rle(mug)/(omega^(2))`

D

`rge(mug)/(omega^(2))`

Text Solution

Verified by Experts

The correct Answer is:
C
When the disc spins the frictional force between the gramphone record and coin is `mumg`
The coin will revolve with record, if
`F_(frictionalgeF_(centripetal)`
`mumggemomega^(@)r`
`(mug)/(r)geomega^(2)` .
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Knowledge Check

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